The present disclosure relates to a seat device of a vehicle, the seat device including a seat on which a rider of the vehicle is seated. The present disclosure particularly relates to a seat device in which both of width direction end areas of a seating surface of the seat are turned by actions of action bodies provided at both of width direction end portions of the seat.
As a characteristic of a seat that a rider straddles to be seated thereon, like a seat installed on a motorcycle, sitting pressure (body pressure) distribution during traveling is required. Here, the sitting pressure distribution refers to a degree of distribution of a force that the rider exerts to the seat during traveling, and as the distribution is higher, the load on the rider (so-called tiredness from sitting) is reduced.
On the other hand, in order to improve the above-described sitting pressure distribution, a contact area of the seating surface of the seat with the rider's buttocks may be increased by holding up and supporting the rider's thighs, or the like, during traveling. As a configuration for holding the rider's thighs during traveling, for example, the configuration disclosed in Japanese Patent Publication JP 4381093 can be used. In the seat disclosed in Japanese Patent Publication JP 4381093, air cushions are provided between a bottom plate and an outer layer member, so that the shape of the seating surface of the seat can be changed by adjusting the internal air pressure of the air cushion.
More specifically, in the seat disclosed in Japanese Patent Publication JP 4381093, the above-described air cushions are positioned at both of width direction end portions of the seat, the inflation of the air cushion causes both of the width direction end areas of the seating surface of the seat to move in such a direction that the end areas are separated from the ground. In such a state, the thighs of the rider seated on the seat are lifted up, so that the sitting pressure is distributed appropriately.
According to the configuration, as in Japanese Patent Publication JP 4381093, in which action bodies such as air cushions are arranged at both of the end portions in a width direction of the seat and are caused to act to change the shape of the seating surface of the seat, parts surrounding the action bodies, which are more specifically cushion members and an outer layer member arranged above the action bodies, also move, following the action of the action bodies. Here, it is desirable that the motions of these members can follow the movements of the action bodies excellently. On the other hand, the cushion members, the outer layer member, and the like are required to have certain hardness or firmness from the viewpoint of shape keeping. It is therefore required to retain the shape during a normal time, and to cause the cushion members and the outer layer member to follow the movements of the action bodies when the shape of the seating surface of the seat is changed. It is however difficult for conventional configurations including that of Japanese Patent Publication JP 4381093 to satisfy the above-described requisition, which possibly makes it difficult to change the shape of the seating surface of the seat.
Further, the action bodies and equipment attached thereto (for example, an actuator as a power source) have to be arranged at positions at which they can exhibit the functionalities thereof excellently, and they do not adversely influence the seating properties (e.g., sitting comfort).